Sindhi helmet with face guard

[Radu Transylvanicus]

And the Normans and the Vikings as well had somehow similar helmets ... but yes it is a good chance that the pre Byzantine Greek archaic helmets are the source (remember those Corinthian and "hoplite" helmets?) ... Not necesarilly with detachable masks but it if I dig some bibliography maybe I will find that too ...
Remember that "boomerang" theory comming from ancient Greece to Hindoostan ( kopis - sossun pata - khukri - yathagan ) ...
Back in Romania in the Orthodox (Eastearn) iconography there are many examples of a half sphere sometimes conical helmets with nasal (metal strip) protection and chainmail but they are definatelly not singular examples , however not detachable masks that I can remember ....
However you fueled me a great ideea about posting a helmet from ancient Romania ( Dacia ) I had the privilege of examining close , a national treasure belonging to local Thracs but I will open a separate thread on that so we stay focus on your thematic but yes, the Forum does need more talk about helmets and head protection .. Good catch, Jim !
Could this type of ancient Greek helmet be the part of the evolutionary course to the "Helmet of Sind" ?